Wireless communication networks may be used for numerous applications including tactical military and commercial applications. Tactical military and commercial applications require self-organizing, wireless networks that can operate in dynamic environments and provide peer-to-peer, multi-hop, multi-media communications. A structured wireless channel access scheme such as Time Division Multiple Access (TDMA) may be used in an ad hoc wireless network. TDMA is a channel access technique in which a frequency channel is divided into time slots and each time slot is assigned to a user. Accordingly, multiple transmissions may be supported on a single frequency channel.
Wireless ad hoc networks form topologies ranging from very sparse to fully connected graphs. Multiple channels may be used to allow simultaneous communication of neighboring nodes, for example, in a network with a dense topology. A multi-channel (or multi-frequency) TDMA access scheme such as Orthogonal Domain Multiple Access (ODMA) may be utilized to support multiple channels. Multi-channel time division multiple access is the subject of U.S. Pat. Nos. 5,949,760; 6,317,436; 6,331,973; 6,487,186; 6,504,829; 6,515,973; 6,574,199; 6,574,206; 6,600,754; 6,628,636 and 6,711,177, the disclosures of which are herein incorporated by reference.
In a multi-channel network, subsets of nodes in the network may be grouped on a particular frequency or channel (i.e., nodes are formed into a channelized group or neighborhood). A channelized group of nodes may be formed for each channel of the multi-channel network. Typically, each node belongs to only one channelized group at a time, but a node may operate on two or more channelized groups to allow inter-channel communications. As the topology of a network changes (i.e., mobile nodes move positions), however, it is possible that there may be interference or contention in a channelized group on the associated channel.
Accordingly, there is a need for a system and method for forming channelized groups of nodes in order to avoid contention on any single channel of a multi-channel communication network. There is also a need for a system and method to determine if there is contention on a particular channel and to determine when a node should change its channel (i.e., switch to a different channelized group) to avoid contention.
It would be desirable to provide a system and/or method that provides one or more of these or other advantageous features. Other features and advantages will be made apparent from the present specification. The teachings disclosed extend to those embodiments which fall within the scope of the appended claims, regardless of whether they accomplish one or more of the aforementioned needs.